A flash unit charging-control circuit for a camera includes a voltage
converter connected to a flash unit capacitor, a square-wave oscillator
for causing current supplied by the voltage converter from a power supply
battery to the flash unit capacitor that relieves a substantial burden on
the MCU of the camera, and a current control circuit. When the battery
voltage becomes low, the current control circuit will regulate the
charging current so as to slow the decrease in battery voltage during
charging.
